1. Field
The present disclosure relates to a driving force distribution control apparatus for a four-wheel drive vehicle and a driving force distribution control method for a four-wheel drive vehicle.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 4-103433 describes a torque split four-wheel drive vehicle that directly transfers the driving force of an engine to one of front and rear wheels (a primary drive wheel) and a driving force divided by a torque split clutch to the other wheel (a secondary drive wheel). The technique for controlling the torque distribution ratio described in Japanese Unexamined Patent Application Publication No. 4-103433 is basically a technique for performing control to cause a difference in a rotational speed between the front and rear wheels to converge to zero and, in particular, a technique for detecting a difference between the diameters of the front and rear tires and performing driving force distribution control using the rotational speed difference between the front and rear tires corrected in accordance with the difference between the tire diameters and the vehicle speed. In addition, Japanese Unexamined Patent Application Publication No. 2007-302024 describes a technique for performing driving force distribution control while taking into account the lateral acceleration.